Knee brace for aiding patellar tracking

ABSTRACT

Knee braces for various uses, e.g., restricting anterior tibial movement. The braces include a frame, leg mounting straps, and a pressure applicator. The frame is made up of an integral unit including a pair of elongated support rods and a bridging member connecting the rods. In one embodiment the pressure applicator comprises a posterior thigh restraining strap, a portion of the bridging member and a calf cuff pivotally connected to that portion of the bridging member by a single anterior pivot so that the calf cuff can pivot about plural axes with respect to the bridging member. The frame is movably coupled to the upper leg of the person so that the rods can translate forwardly, along the medial and lateral sides of the upper leg, respectively, until the restraining strap resists such forward movement. With the pressure applicator projecting outward from the axes of the rods for fixed anterior positioning relative to the tibia tubercle of the person and with the forward translation of the rods being restrained, resistance to anterior movement of the tibia increases as the person&#39;s knee is extended. In another embodiment the brace is arranged to be mounted on the lower leg of the person so that the bridging member applies pressure to the patella and thereby isolate it from the irritated tibia tubercle to reduce the pain associated with Osgood Schlatter&#39;s Disease. In another embodiment the brace includes a web of elastic material having a patellar opening for mounting over the patella of the person to aid in patellar tracking.

This application is a divisional of application Ser. No. 08/207,780,filed on Mar 8,1994, now U.S. Pat. No. 5,433,699.

SPECIFICATION

This invention relates generally to orthopedic knee braces, and moreparticularly to knee braces for use by persons having anterior cruciateligament laxity or insufficiency to protect them from injury due toabnormal anterior tibial movement.

1. Background of the Invention

Various types of knee braces are shown in the patent literature and arecommercially available. The following constitute examples of prior artbraces that deal with restricting anterior movement of the tibia foundin the following U.S. Pat. No.: 4,751,920 (Mauldin et al.); 4,781,180(Solomonow) and U.S. Pat. No. 4,955,369 (Bledsoe, et al).

The apparatus shown by Mauldin is a knee brace that has a firstattachment portion to attach the brace to the wearer's thigh and asecond attachment portion to attach the brace to the wearer's tibia anda hinge connected to the medial side of the first and second attachmentportions by way of a thigh bar and tibia bar, respectively. Anadjustable gearing mechanism located at the hinge permits the wearer tolimit the amount of rotation of the tibia bar with respect to the thighbar. However, this brace suffers from failing to be able to preventanterior translation of the tibia by the application of posteriorpressure directly at the tibia tubercle location. Instead, like itspredecessors, the Mauldin apparatus attempts to limit tibial rotation bylimiting medial hinge motion.

The apparatus shown by Solomonow is a knee brace having an upperframework attached to the thigh and a lower framework attached to thelower leg just below the knee. These two frameworks are hinged on themedial and lateral sides of the leg (bilateral hinge). A bell crank ispivotally connected to the lower framework. An adjustable screw coupledto one side of the bell crank engages an offset portion of the upperframework whenever the leg is extended. The other side of the bell crankis coupled to a tibial restraining strap. As the leg is extended, thelower framework and bell crank are rotated counterclockwise until theoffset of the upper framework contacts the screw, rotating the bellcrank in a clockwise direction and thereby tightening the tibialrestraining strap against anterior movement of the tibia.

The apparatus shown by Bledsoe et. al is a knee brace which alsoutilizes bilateral hinges to connect the thigh support and calf supportsections. The bilateral hinges basically comprise adjustable driveplates that alternate the pivoting point of the thigh support and calfsupport throughout leg flexion and extension. By varying the pivot pointat different points throughout leg extension, a counter shearing forceis generated to reduce the shearing force created by the quadricepsmuscle which cause the undesirable anterior shift of the tibia of theleg.

Examples of prior art knee braces which are commercially available are:DONJOY 4-Point™, GoldPoint™, and Playmaker™ all of which are sold bySmith & Nephew Donjoy Inc. of Carlsbad, Calif.; Innovation Sports C.T.I.Standard, Super-Light and Pro-Start, C.T.I.², MVP, and Sentry all ofwhich are sold by Innovation Sports of Irvine, Calif.; Cincinatti ACLwhich is sold by Brace Technologies Inc. of Cincinatti, Ohio; OS-5™which is sold by Omni Scientific, Inc. of Martinez, Calif.; and theLennox Hill™ OTS and Spectralite which are sold by 3M Health Care ofLong Island City, N.Y. Many of the foregoing braces, while suitable fortheir intended purposes nevertheless suffer from a common problem,namely, they fail to adequately restrict abnormal anterior tibialmovement. All of these conventional braces, basically, comprise a topcuff (or pad), a bottom cuff (or pad), a hinge in the middle (located onthe medial side, lateral side or on both of these sides of the leg,i.e., bilateral hinge) and straps to affix the brace to the leg.Although such configurations are satisfactory for dealing withside-of-the-knee injuries, these braces permit the natural motion of theleg which means that they also do not prevent anterior translation ofthe tibia.

Another type of knee disorder that is common in adolescent males isknown as Osgood Schlatter's Disease (OSD). OSD is the partial tearing ofa growing tibial tubercle, manifested by subcutaneous swelling over thetibial tubercle and is aggravated by running or by kneeling on, orsustaining direct blows to, the tibia tubercle location. A conventionalmethod of treating OSD is by the use of a device known as a Cho-Patstrap which is sold by Cho-Pat, Inc. of Hainesport, N.J. This strapalleviates the pain associated with OSD by maintaining the patella outof the way of the irritated area. In particular, the strap encompassesthe entire circumference about the knee, just under the patella. Thedisadvantage of this device is that it must be tied tightly about theknee, cutting off blood flow to the calf causing cramping. Moreover,because the strap encompasses the entire circumference of the knee, ittends to bind or encumber the knee location whenever the wearer bendshis knee, i.e., it is uncomfortable during sitting or squatting.

Another type of knee disorder is an untracked patella. In a normal knee,as the knee is bent, the patella orients itself into the trochleargroove. When the leg is extended, the patella emerges from that groove.In some cases during this extension, this removal from the trochleargroove makes the patella vulnerable by going out of socket. To guide thepatella and ensure that it tracks freely and smoothly, the conventionalmeans used is, in essence, a sleeve with a hole located at the patellawhich surrounds the knee cap. However, the disadvantage of this designis that as the leg is extended, i.e., when the patella is mostvulnerable, the hole puckers, thereby reducing tension applied aroundthe knee cap. Reduction in tension during extension is just the oppositeof what is needed: one wants tension to increase around the knee cap asthe knee is extended in order to keep the patella aligned.

2. Objects Of The Invention

Accordingly, it is the general object of this invention to provide aknee brace which overcomes the disadvantages of the prior art.

It is a another object of this invention to provide a knee brace forrestricting abnormal anterior tibial movement.

It is a further object of this invention to provide a knee brace forrestricting abnormal anterior tibial movement without preventing thewearer from being able to fully extend his/her leg.

It is still yet another object of this invention to provide such a bracethat is less expensive than the conventional knee brace

It is still a further object of this invention to provide such a bracethat is lightweight.

It is still a further object of this invention to provide a brace fortreating Osgood Schlatter's Disease that does not require a strap betightly affixed around the lower leg, just under the patella, whichreduces blood flow to the calf, causing cramping.

It is still a further object of this invention to provide a brace fortreating Osgood Schlatter's Disease that does not bind or put pressurebehind the knee area when the leg is flexed.

It is still yet a further object of this invention to provide a bracefor aiding in patellar tracking.

It is still yet a further object of this invention to provide a bracefor aiding in patellar tracking that increases tension, necessary forproper tracking, to the patella as the leg is extended.

SUMMARY OF THE INVENTION

These and other objects of the instant invention are achieved byproviding a knee brace restricting anterior tibial movement of a personcomprising translatable frame means, frame mounting means, restrainingmeans, and tibial pressure application means. The frame means comprisesa pair of elongated support rods each having an upper end and a lowerend, and a bridging member connecting the lower ends of said supportrods. Each of the support rods has a longitudinal axis.

The restraining means is connected between the support rods for receiptof a portion of the posterior of the person's upper leg therein. Thetibial pressure application means comprises a first portion of thebridging member.

The support rods are coupled, e.g., releasably secured, to the framemounting means for mounting the support rods on the upper leg of theperson wearing the brace so that they extend respectively along themedial and lateral sides of the upper leg, with the tibial pressureapplication means projecting forwardly outward from the axes of thesupport rods so that the tibial pressure application means can bebrought into a fixed anterior position relative to the tibia tubercle ofthe person when the leg of the person is extended.

The upper end of each support rod is also movably coupled to the framemounting means in such a manner, whereupon when the leg of the person isextended the movable coupling of the upper ends of said support rods tothe frame mounting means enables the support rods to pivotally translatein a forward direction so that their respective axes are disposedgenerally parallel to the longitudinal axis of the upper leg. Therestraining means serves to oppose the forward pivotal translation sothat the tibial pressure application means is held in a fixed anteriorposition relative to the tibia tubercle of the person to provideresistance to anterior movement of the tibia when the leg is extended.

The upper end of each support rod is also movably coupled to the framemounting means in such a manner, whereupon when the leg of the person isbent the movable coupling of the upper ends of the support rods to theframe mounting means enables the support rods to pivotally translate ina rearward direction so that their respective axes are disposed at anacute angle with respect to the longitudinal axis of the upper leg ofthe person, thereby releasing the resistance to the anterior movement ofthe tibia.

In accordance with one preferred embodiment of the invention the kneebrace includes cuff means for securement to the calf of the person. Thecuff means comprises an engagement portion for engaging the lower leg ofthe person contiguous with the tibia tubercle. The engagement portion ofthe cuff means is preferably coupled to the tibial pressure applicationmeans by articulating hinge means.

DESCRIPTION OF THE DRAWINGS

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings wherein:

FIG. 1 is a side view of the knee brace for restricting anterior tibialmovement attached to the patient's leg (shown in phantom) during partialleg extension;

FIG. 2 is a side view similar to that of FIG. 1 but showing thepatient's leg during full leg extension;

FIG. 3 is a front view of the knee brace on the fully extended leg(shown in phantom);

FIG. 4 is a reduced isometric view of the knee brace of FIG. 1;

FIG. 5 is a side view of the knee brace like that of FIG. 1 but showingpatient's leg when the knee is bent at approximately 90°;

FIG. 6 is an enlarged sectional view taken along line 6--6 of FIG. 2;

FIG. 7 is an enlarged sectional view taken along line 7--7 of FIG. 2;

FIG. 8 is an enlarged sectional view taken along line 8--8 of FIG. 3;

FIG. 9 is an enlarged sectional view taken along line 9--9 of FIG. 3;

FIG. 10 is an isometric view of an alternative embodiment of the bracefor use with patients having Osgood Schlatter's Disease;

FIG. 11 is a side view of the brace of FIG. 10 shown attached to thepatient's leg (shown in phantom);

FIG. 12 is a partial isometric view of the brace of FIG. 10 showing anoptional protective cover for the tibia tubercle mounted thereon;

FIG. 13 is a front view similar to FIG. 3 but showing yet anotheralternative embodiment of a knee brace, this brace being for patellartracking and is shown during full extension of the leg ( shown inphantom);

FIG. 14 is a side view similar to FIG. 13 of the knee brace for patellartracking; and

FIG. 15 is a side view of yet another embodiment of the knee brace forrestricting anterior tibial movement using a neoprene sleeve attached tothe patient's leg during full leg extension.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now in detail to the various figures of the drawing whereinlike reference characters refer to like parts, there is shown at 20 inFIG. 1 a knee brace constructed in accordance with this inventionattached to the wearer's right leg. (The right leg is chosen forconvenience only; this device can be affixed to either the right or leftleg). As more clearly shown in FIG. 4, the brace 20 comprises a pair ofelongated support rods, 22A and 22B, that are positioned on the medialand lateral sides of the upper leg 24 (FIG. 1), respectively. The twosupport rods 22A and 22B are coupled to one another at their respectivelower ends 26A and 26B by way of a bridging member 28, thereby forming a"U-shaped" frame which can be more easily seen in FIG. 3. The centerportion of the bridging member 28 serves to apply pressure to the tibiaand hence defines the tibia pressure application means 44 (to bedescribed later).

The support rods 22A and 22B are also coupled to one another at theirmidsections by way of a restraining strap 30. As will be discussedlater, this restraining strap 30 fits snugly around the back portion ofthe thigh of the wearer's upper leg 24 while coupling the midsections ofthe support rods 22A and 22B together. The support rods 2A and 22B,bridging member 28 and restraining strap 30 are coupled to the wearer'sleg by way of a frame mounting means (to be described hereinafter).

The frame mounting means releasably secures the "U-shaped" frame to theupper leg 24 and calf 32 of the wearer and comprises an upper strap 34that encircles the upper leg 24, a calf cuff 36, and associated calfcuff straps 38A and 38B that affix the brace 20 to the wearer's calf 32.As can be seen in FIGS. 3 and 4, the upper strap 34 couples the upperends 40A and 40B, respectively, of the support rods 22A and 22B to theupper leg 24. Furthermore, as can be seen in FIG. 6, and as will bediscussed in more detail later, this coupling is movable, allowing thesupport rods 22A and 22B to pivotally translate in a forward or backwarddirection with respect to the longitudinal axis of the wearer's upperleg about their upper ends 40A and 40B. It should be noted at the outsetthat the components of this frame mounting means are by way of exampleand not limitation, i.e., a variety of different attachmentconfigurations could be easily substituted for these straps 34, 38A and38B and cuff 36. The details of these items will be discussed later.

The calf cuff 36 is mounted on bridging member 28 by way of anarticulating hinge 42. As will be discussed later, this hinge 42maintains the tibial pressure application means 44 at a fixed anteriorposition relative to the tibia tubercle (not shown) of the wearer, suchthat increasing pressure is applied to the tibia as the wearer causeshis/her leg to be extended, thereby resisting undesirable anteriormovement of the tibia. Because it is an articulating hinge, hinge 42 canorient the tibial pressure application means in a position to maintainpressure against the tibia regardless if the leg is turned right orleft. Again, it should be noted at the outset that the articulatinghinge 42 is by way of example and not limitation, i.e., a variety ofdifferent articulating hinges could be easily substituted for the hinge42.

The bridging member 28 is offset from each support rod 22A by apredetermined angle α with respect to each of the longitudinal axes 46Aand 46B (FIG. 4) of the support rod 22A and 22B, respectively. Theoffset α is selected to be in the range of between 30° and 60° withrespect to the longitudinal axes 46A and 46B, as shown in FIG. 5. Thisoffset assures that the support rods 22A and 22B remain situated alongthe medial and lateral sides of the leg, respectively, throughout theentire range of leg movement, i.e., from a bent knee (FIG. 5,hereinafter known as the "90° position") to full extension (FIG. 2,hereinafter known as the 0° position"). Without the offset α, i.e., ifthe frame were coplanar, extending the leg would drive the frame out ofposition. Instead the offset bridging member 28 allows the leg to bepivoted into the space bounded by the offset bridging member 28 untilthe tibial pressure application means 44 makes contact with the tibialtubercle. Furthermore, since the bridging member 28 is of an arcuateshape (FIG. 4) it can abut the area surrounding the knee when the leg isfully extended, while minimizing the amount of projection away from theknee that the bridging member 28 exhibits when the leg is bent (FIG. 5).Therefore, the combination of the offset α and the arcuate shape of thebridging member 28 maintain the bridging member as close to the knee aspossible throughout full knee flexion and extension.

Operation of the knee brace 20 can be explained as follows. Starting inFIG. 5, at the 90° position (where the knee is bent), there is nopressure being asserted against the tibia by the bridging member 28 atthe hinge 42 location. Note that the longitudinal axis 46A of supportrod 22A forms an acute angle B with respect to the longitudinal axis 50of the upper leg 24 of the wearer when the knee is bent. The angle β isbetween 0° and approximately 30°. As the leg is extended, the upper ends40A and 40B of the support rods 22A and 22B pivot about an axis 52normal to the medial side of the upper leg 24 (FIGS. 2 and 3), wherebythe lower ends of support rods 22A and 22B translate in a forwarddirection so that the support rod axes 46A and 46B assume a positiongenerally parallel to the upper thigh longitudinal axis 50 as shown inFIG. 2. The restraining strap 30 tends to resist this forwardtranslation. This resistance causes the tibial pressure applicationmeans 44 (to be described later) to be held in a fixed anterior positionrelative to the tibia tubercle (not shown) of the wearer, therebycreating a resistive force in the posterior direction against anteriormovement of the tibia when it engages the tibial pressure applicationmeans 44. This resistive force is first sensed by the wearer when theleg has been extended down to approximately the 30° position andincreases as the leg reaches the fully extended position due to theopposition of the restraining strap 30 to the support rods'22A and 22Bforward translation. When the leg reaches the 0° position (i.e., fullyextended as shown in FIG. 2), the restraining strap 30 maintains thesupport rods 22A and 22B such that their respective longitudinal axes,46A and 46B are generally parallel to the upper thigh longitudinal axis50. In this position, the resistive force against the tibia, provided bythe tibial pressure application means 44, is at its maximum, therebypreventing any further forward translation of the tibia.

As shown in FIGS. 1 and 2, the restraining force exerted by therestraining strap 30 tends to "bow" the support rods 22A and 22Bsomewhat, thereby preventing any further forward translation of thesupport rods, 22A and 22B, and thereby anchoring the bridging member 28with respect to the leg. This latter action prevents any forwardmovement of the tibia. These views (shown in FIGS. 1 and 2) areexaggerated in that the amount of "bow" of the supporting rods due tothe restraining strap 30 may actually be very subtle.

Because the restraining strap 30 resists the forward translation of thesupport rods 22A and 22B, the strap 30 may tend to "dig" or "bite" intothe wearer's posterior portion of the thigh. Therefore, a shield 54(FIG. 2) is provided for insertion between that portion of the wearer'sthigh and the restraining strap 30 to eliminate any discomfort caused bythe tightening strap 30.

The operation of the brace from full extension to flexion is as followswhen the wearer flexes his or her leg: starting from the 0° position andthen flexing his or her leg towards the 90° position, as the calf 32reaches the 30° position the resistive force diminishes as the supportrods 22A and 22B translate in a rearward direction, pivoting about theirupper ends 40A and 40B towards the posterior of the thigh. Therefore,the restraining strap 30 relaxes and there is no longer any resistiveforce being applied to the tibia. The support rods 22A and 22B come torest in a position where their respective longitudinal axes 46A and 46Bform the acute angle β, thereby maintaining the bridging member 28 andarticulating hinge 42 close to the knee location, while not obstructingany further flexion of the leg.

The following discussion concerns the detail of the indicated componentsof the knee brace 20.

The frame, composed of the rods 22A and 22B and the bridging member 28,is preferably formed as an integral unit of any suitable strongmaterial, e.g., carbon graphite, preferably fiberglass with carbon fiberbraid. Even aircraft aluminum could be used.

As can be seen in FIG. 4 and appreciated by those skilled in the art,the upper end of the cuff 36 provides a surface upon which a portion ofthe articulating hinge 42 is fixedly secured. The articulating hinge 42will be described in detail later with reference to FIG. 8. Suffice itfor now to state that it basically comprises a strap of any suitableflexible material, e.g., woven nylon which is folded over itself to forma passageway 42A through which the central portion of the ridging member28 extends. The strap forming the hinge extends through a horizontalslot in the upper end of the cuff 36 and is held in place by cooperatingVELCRO® fasteners.

Any means, e.g., a neoprene sleeve 56 (FIG. 15), can be used in lieu ofthe cuff 36 to mount the articulating hinge 42 on the bridging member28. If such a sleeve is used, an additional strap 58 is necessary tosecure the support rods 22A and 22B to the front of the leg. If a rigidcuff 36 is used, the cuff is preferably made of polyethylene (or anycopolymer). Certainly, because the cuff 36, as shown in FIGS. 1-5,comprises a rigid surface, the effect of having the articulating hinge42 mounted thereon results in the upper portion of the cuff 36 aidingthe bridging member 28 in distributing the force against anteriortranslation of the tibia.

As stated previously, the upper cuff strap 38A and lower cuff strap 38Bprovide the releasable securement of the cuff 36 to the calf 32. Eachstrap 38A and 38B is slipped through and then looped around rings 60.The rings 60 are trapped in brackets 62 to form hinged rings. Thebrackets 62 are coupled to the cuff 36 by way of rivets 66. The ends ofstraps 38A and 38B each include a VELCRO® hook patch 68 (FIG. 2) thatreleasably engages the plush outer surface of the straps 38A and 38B.The other ends of the straps 38A and 38B are secured to the cuff 36 viabrackets 62 including hinged rings 60. The brackets 62 are riveted tothe cuff 36 by rivets 66. The straps 38A and 38B extend through theassociated hinged rings 60 and the VELCRO® hook patch 68 on the strap38A is brought into engagement with the plush surface of the strap 38A,thereby permitting the strap 38A to be tightened or loosened forcomfort. The strap 38B is mounted and adjusted in a similar manner.

FIG. 6 depicts a top view of the upper strap 34 which comprises ananterior thigh strap 70 and a posterior thigh strap 72. The anteriorthigh strap 70 is looped around support rods 22A and 22B and folded backupon itself, with the inner side of the free ends of strap 70 being inthe form of a VELCRO® hook patch 74 that engages the plush outer side ofthe strap 70. Each upper end 40A and 40B of support rods 22A and 22B,respectively, includes a hook patch 76A and 76B, respectively, ofVELCRO® secured about its periphery with the hooks projecting out toreleasably engage the plush inner surface of the strap. This looping ofthe thigh strap 70 to releasably secure the upper ends of the rodscreates the movable coupling between the upper ends 40A and 40B of thesupport rods 22A and 22B to the upper thigh 24 of the wearer whilepermitting the support rods 22A and 22B to pivotally translate aboutaxis 52. The VELCRO® hook patches 76A and 76B are affixed (e.g., glued)about the circumference of the upper ends 40A and 40B. The ends of theposterior thigh strap 72 also have VELCRO® hook patches 78 that engagethe plush outer surface of anterior thigh strap 70. The VELCRO® hookpatches 78 provide the means to tighten or loosen the upper strap 34 forcorrect fit around the upper thigh 24.

FIG. 7 depicts a top view of the restraining strap 30. This strap 30 isattached to the support rods 22A and 22B in the identical manner asdescribed above with regard to the anterior thigh strap 70.

FIG. 9 depicts the means by which the restraining strap 30 is loopedaround one of the support rods. On this regard the support rod 22A (or22B) has its own VELCRO® hook patch 80 that is affixed (e.g., glued) toengage a plush portion of the restraining strap 30. This engagementassures that the restraining strap 30 maintains its coupling to thesupport rod 22A and 22B midsections.

FIG. 8 depicts a cross-sectional view of the articulating hinge 42 ofFIG. 1. The hinge 42 is formed of a pliable sleeve 82 that is looped toform passageway 42A which receives and traps the central portion of thebridging member 28 therein. The sleeve 82 is formed by a looping of awoven material, e.g., nylon, strip 84 that is affixed through the upperpart of cuff 36 by an aperture or slot 86. The sleeve 82 gives thebridging member 28 the ability to articulate in many directions. Thematerial strip 84 loops around the upper portion of the cuff 36 and isthen fastened to the cuff's 36 outer surface by a VELCRO® hook patch 88adhesively secured to the outer surface of the upper end of the cuff 36.An inner VELCRO® plush patch 90 is located on an end of the strap 84 tomaintain a tight fit of the material strip 84 to the cuff 36.

A similar configuration of this brace can be used in the treatment ofOsgood Schlatter's Disease. In FIG. 10, there is shown a brace 92comprising a frame means, a frame mounting means and a pressureapplication means. The frame means is basically identical to that of thebrace 20 of FIG. 1 and comprises a pair of elongated support rods 94Aand 94B, having longitudinal axes 96A and 96B, respectively. The rodsare connected to each other by a bridging member 98. As with thebridging member 28, the bridging member 98 is also arcuate in shape andforms an offset α' (FIG. 11) with respect to each support rodlongitudinal axis 96A and 96B for purposes similar to the ones discussedabove concerning offset e. The frame mounting means comprises a lowerstrap 102 for affixing the brace 92 to the right calf (as statedearlier, the right calf is chosen for convenience only; the brace 92could be affixed to either the left or right calf) and a stabilizingstrap 104. These straps 102 and 104 are coupled to the support rods 94Aand 94B in the same manner as the upper strap 34 and restraining strap30, respectively, are coupled to support rods 22A and 22B, as discussedabove. The pressure application means comprises a portion of thebridging member 98 that rests just under the patella (in particular, thebridging member 98 is oriented at the patella notch, i.e., the distalportion of the patella tendon) when the brace 92 is mounted to the calf32 and the leg is in an extended position (FIG. 11). A bridging membercushion 106 (e.g., foam cushion) is disposed on the bridging member 98for the wearer's comfort.

Operation of the brace 92 occurs during extension of the leg as follows.With the brace 92 mounted to the calf 32, the bridging member 98 islocated horizontally across the infrapatellar region, between theinferior pole of the patella and the tibial tubercle. As the leg isextended, the bridging member 98 increases pressure on that region tomaintain the patella away from the irritated area 108 (e.g., an enlargedtibial tuberosity). As the leg is extended, the patella presses downwardagainst the bridging member 98 which increases its resistance to thisdownward movement due to the fixed position of the support rods 94A and94B.

The advantage of this brace 92 over the conventional treatment, theCho-Pat strap, is that pressure is applied to the patella withoutreducing blood flow to the leg and thereby avoids cramping of the calf.In addition, when the wearer of the brace 92 is seated or in a squattingposition where the knee is bent, there is no encumbrance under the kneeto cause discomfort.

An optional protective cover 110 can be coupled to the brace 92, asshown in FIG. 12, to protect the tibial tubercle in addition to treatingthe pain associated with OSD. The protective cover has a pad 112 on itsinner side to create a cushion between the cover 110 and the tibialtubercle location.

Another similar brace configuration that is used in aiding patellartracking is shown in FIGS. 13 and 14. This brace 114 comprises a framemeans, frame mounting means and a pressure application means. The framemeans comprises a pair of elongated rods 116A and 116B, havinglongitudinal axes 118A and 118B, respectively, and are connected to oneanother by a bridging member 120. As with the bridging member 28, thebridging member 120 is also arcuate in shape and forms an offset α"(FIG. 14) with respect to each support rod longitudinal axis 118A and118B for purposes similar to the ones discussed above concerning theoffset α. Although in brace 114 the bridging member 120 is disposed overthe anterior portion of the calf 32 rather than just under the knee asin the brace 92, the arcuate shape of the bridging member 120 and theoffset α" serve to maintain the support rods 116A and 116B along themedial and lateral sides of the calf 32 throughout leg flexion andextension while minimizing the amount of projection of the frame meansaway from the surface of the calf 32.

The frame mounting means comprises a middle strap 124 and a lower strap126. These straps affix and stabilize the elongated rods 116A and 116Balong the medial and lateral sides of the right leg calf 32 (the rightleg was chosen for convenience only; the brace 114 could be affixed tothe left or the right legs). The upper ends of the elongated rods arecoupled to the pressure application means, which in this instancecomprises a member 128, having a hole 130 that is fitted over thewearer's patella. As the knee is extended from a bent position, themember 128 increases pressure about the patella to maintain thealignment of the patella as it emerges from the trochlear groove (notshown). The rods 116A and 116B maintain the member's 128 position on thepatella, thereby avoiding the "puckering" that normally occurs in otherpatellar tracking devices. The member 128 may comprise any variety ofmaterials (e.g., elastic, inelastic or any combination thereof),depending on the amount and direction of pressure to be applied to thepatella.

The straps 124 and 126 are attached to the support rods 116A and 116B ina similar manner as the restraining strap 30 is attached to the supportrods 22A and 22B. The member 128 is attached to the support rods 116Aand 116B in a similar manner as the anterior thigh strap 70 discussedabove. A bridging member cushion 132 (e.g., foam cushion) is alsodisposed around the bridging member 118 for the wearer's comfort.

Without further elaboration, the foregoing will so fully illustrate myinvention that others may, by applying current or future knowledge,readily adopt the same for use under various conditions of service.

I claim:
 1. A brace for securement on the lower leg of a person to aidpatellar tracking of the person while enabling the knee to bend, saidbrace comprising frame means, frame mounting means, and pressureapplication means, said frame means comprising a pair of elongatedsupport rods and a bridging member, each of said support rods having alongitudinal axis, a lower end, and an upper free end, said bridgingmember being located between said bottom end of each of said supportrods, said support rods being coupled to said frame mounting means formounting said support rods so that they extend respectively along themedial and lateral sides of the person's lower leg, with said bridgingmember projecting outward from the axes of said support rods to receivea portion of the person's lower leg therein and with said free ends ofsaid support rods being adapted to located on the lateral and medialsides of the person's knee, said upper free ends of said support rodssupporting said pressure application means therebetween to form the topof said brace, said pressure application means comprising a memberhaving an opening for receiving the person's patella therein, whereuponsaid pressure application means provides assistance in patellartracking.
 2. The knee brace of claim 1 wherein said frame mounting meanscomprises at least one strap for releasably encircling a portion of theperson's calf.
 3. The knee brace of claim 1 wherein said member has anopening for receiving the person's patella therein comprises an elasticmaterial.